25991616 has 112 divisors (see below), whose sum is σ = 79881984. Its totient is φ = 7305216.

The previous prime is 25991599. The next prime is 25991629. The reversal of 25991616 is 61619952.

It is a tau number, because it is divible by the number of its divisors (112).

It is a nialpdrome in base 12.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111436 + ... + 111668.

It is an arithmetic number, because the mean of its divisors is an integer number (713232).

Almost surely, 2^25991616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25991616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39940992).

25991616 is an abundant number, since it is smaller than the sum of its proper divisors (53890368).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25991616 is a wasteful number, since it uses less digits than its factorization.

25991616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338 (or 328 counting only the distinct ones).

The product of its digits is 29160, while the sum is 39.

The square root of 25991616 is about 5098.1973284682. The cubic root of 25991616 is about 296.2177603827.

The spelling of 25991616 in words is "twenty-five million, nine hundred ninety-one thousand, six hundred sixteen".